Protect your herd at grazing

Ruminants have a poor capability to store magnesium, with 70% of body reserves held in the skeleton and the remainder distributed in the soft tissue and fluids of the animal. Adsorption, occurs throughout the digestive tract, but is primarily confined to the rumen and reticulum once the mineral is readily soluble. Hypomagnesaemia, or more commonly known as grass tetany/grass staggers results from this poor ability to store and absorb (Mg) and is especially prevalent in dairy and beef cows. Higher yielding, older lactating cows are most susceptible to the disease, as high levels of (Mg) excretion occurs during milk production. Only exceptional cases of grass tetany have been recorded in none-lactating cows.

Symptoms occur quite rapidly in the animal, as the nerve system is affected. Severe muscle contractions, an irregular and loud heartbeat, unnecessary bellowing while grazing and convulsions are all clinical signs. Due to the short duration of these symptoms, affected animals are generally found dead with the ground routed and disturbed around them due to thrashing from muscle spasms. However, early warning signs of the disease can be detected in some instances. Reductions in milk yield, loss of body condition and a change in temperament can all be evident in the days prior to convulsions occurring.

A number of different management techniques can be undertaken to prevent the onset of grass tetany. Feeding high (Mg) concentrate, offering high (Mg) molasses based licks or blocks, (Mg) dusting of pastures, supplementing (Mg) into the water supply and incorporating hay or straw into the diet to slow down digestion and allow for increased (Mg) absorption are all options. However consistency of (Mg) uptake can be an issue with some of these preventative measures, especially in periods of high rainfall.

Supplementing (Mg) through a molasses based liquid feed is also a very successful preventative tool that can be used. Introducing Ultra-Mag to the diet at a rate of 1kg/head/day will provide 25g of (Mg), therefore, suppling most cow’s their daily (Mg) requirement under normal weather conditions. In periods of adverse weather, inclusion levels should be increased to 1.0-1.5kg/head/day for periods of moderate risk and 1.5-2.0kg/head/day in high risk periods. Its liquid form, leave it ideal for feeding in liquid feed milking parlours or through robots via liquid feed systems. Additionally it can be topped dressed on forages, mixed with dry feeds, or fed in a diet feeder as part of the TMR. It is important however, to ensure that uniform mixing of Ultra-Mag and other ingredients occurs in the mixer wagon prior to feeding out. Its versatility also allow it to be fed free access through lick wheels or ball feeders